I don’t know why, but I’ve been fascinated with unit testing for years. Yes, you don’t have to point out how nerdy that is, I know, trust me.

I remember thinking that it’s a great idea to be able to check that my code works, all the time and I don’t have to manually do anything … manually …. gosh I really dislike this word. Well, not the word per se, but the activity of spending my precious time, repeatedly doing the same uncreative work.

Am I faster than a computer? No

Am I more accurate? No

Do I have nothing better to do? I do actually

So then, why should I do these activities?

Of course, there is more to it than this, it’s not pure laziness that drives this, it’s more to do with the desire to build quality code, have less bugs and be able to refactor without the fear that everything ends up in the black hole of never again working code. This name itself is scary …. BNAWC, something to do with claws …. yuck.

So, let’s see, what exactly are unit tests? How do we define them and what are their characteristics? I find this is a great place to start as it makes us question, no not life you nerd, but what we are actually doing as part of the coding activity.

A unit test is a piece of code which exercises a small part of our application’s code.

This is a very generic definition and doesn’t help anyone, so let’s move on to characteristics …

unit tests

1. do not touch anything outside of the small piece of code they are testing
2. can be run quickly, repeatedly, without setup and without any specific order
3. are very simple and do not require complex setup, including much mocking
4. do not have deep knowledge of the code they test.

Let’s look at all of these, one by one.

1. Unit tests do not touch anything outside of the small piece of code they are testing.

Unit tests do not touch the file system, a database, an API or anything else like this.

Why?

All these things require a number of things and take some time. You will need a connection string, an API key, the API might even be down, there might be an issue with your database or the API is not even yours but it is a third party one. Does this mean that if this API is down, you cannot complete your tests?

If you have one test and it takes 2 seconds to run, that doesn’t sound so bad. What happens when you have a thousand though?

Are you happy to wait 600 seconds? That’s 10 minutes by the way.

This doesn’t sound so bad until you realize that the whole point of unit tests is that you run them all the time and you even hook them up to your CI/CD pipeline. Now one run takes an extra 10 minutes or more, which is really bad for everyone. You want quick feedback so people don’t even think about this extra test run.

2. can be run quickly, repeatedly, without setup and without any specific order

We’ve already seen why they need to run quickly and without setup.

What about running repeatedly?

This means they don’t affect the state of the system, by calling the code under test, you’re not setting global things, or anything else like that which influences other parts of the code and thus other tests. This means keep your code in check, so that no surprises happen when any piece of code is run.

You don’t want to hunt through your entire codebase trying to find out why the system is in a particular state. This leads into the next one:

3. unit tests are very simple and do not require complex setup, including much mocking

I have seen huge tests doing complex setup over hundreds of lines of code, I’ve seen mocking taken to extreme. Note I did not say don’t do mocking, I said don’t do much mocking, huge distinction.

SOLID encourages you to think about decoupling things, it encourages you to code against abstractions, not hard coded dependencies.

This is good advice, but you can also fall into the trap of doing too much decoupling.

Then, you write a test and you discover that you have to mock dependency A, then dependency B,which now needs dependency C and you keep going down the rabbit hole until you end up with a highly complex setup.

Once you’re done with the test, it looks like a three-headed hydra, big, ugly and scary. All these things make your tests very expensive to maintain, this is why I always advocate for simplicity. If your test looks too ugly, then look at the code because it is not as testable as you thought it was.

4. unit tests do not have deep knowledge of the code they test.

If your code knows too much about the code what happens is that when the code changes ( through refactoring for example ) then your tests will have to change too.

If the behaviour of the code does not change, neither should the tests

This is what makes unit testing worthwhile and cheap to maintain. This is what makes refactoring possible and safe, you have the harness to make sure you don’t break anything so go ahead and refactor to your heart’s content. If the tests are still green then everything is good.

It doesn’t matter how the code changes, your tests, once written have no reason to change, unless the behaviour of the code needs to change. In this case you change the tests, you now have failing tests, you fix the code until tests are green and move on.

If the tests have deep knowledge of the code, then you will have a maintenance nightmare on your hands, the tests will be too expensive to fix every time there is a change, will end up being commented out and the whole thing has been a giant waste of time. This is where it all goes.

What can we do to prevent this from happening?

My advice would be to aim for a functional coding style as much as possible. If a method that you want to test has a number of dependencies passed as parameters for example, then change it and pass data instead.

You can prepare the data first, then pass it to a method, this makes testing very easy because now you don’t have to worry about mocking anything, you just pass the data in whatever format you need.

This is the functional way. Everything a method needs is inside the method, no dependencies at all.

Random thoughts and questions

Is everything suitable for unit testing? I am going to say no.

What is suitable for unit testing? Everything which has a very well defined behaviour, things like an algorithm, formulas, code which changes something in a well defined way. Essentially anything which has business value and can be well defined, without any doubts.

What is not suitable for unit testing? Things which only make sense to developers, a DI setup, things which check how many times a method is called, stuff like that.

Imagine this scenario:

You go and talk to a business analyst ….

hey man, here is this test where I am checking that I am calling a method called RabbitIsJumpingUpAndDownOnOneFoot exactly twice and no less, no more. What do you think about the business value of this method?

If he looks at you like you are a martian with a green head then the answer is no, you should not have that thing. I cannot call it a unit test because it is not.

I have seen some pretty weird things categorized as unit tests, some examples:

When I call this controller I get this specific view back.

What exactly are you testing? That the MVC framework works? Leave that to the framework, that’s not a unit test you should be having.

When my application starts up I verify that all dependencies are injected correctly, with a unit test

nope. you want to check everything is hooked up correctly? Write a few integration tests which rely on the dependencies being correctly injected, then you know everything is set up correctly.

I am testing that this method is called once

what’s the value of this? what happens when the code changes and that method is not called anymore? how do you even know what that method does?

I am testing this code which depends on random values created by this random generator, so I am running this test one thousand times to see what happens when specific values are generated.

Why ? Take the randomness out of your method, generate the thing outside of it, pass the generated thing as a parameter, now you can test your method with specific values, without having to run it like crazy, hoping it will eventually hit the values you want.

I can probably continue like this for quite a while, but hopefully the idea is clear by now. A bit of thought when writing code makes our life a lot easier when it comes to maintaining or changing the code.

The biggest fallacy I’ve ever heard is that unit testing adds whatever percentage ( typically 30 % ) to the delivery time. Let me stop you right there and tell you that is completely wrong.

Why? Writing testable code is no different than writing non-testable code. It’s the same thing as far as delivery is concerned. Adding proper unit tests is very quick, no problem there.

We, as developers debug our code a lot. If we don’t have unit tests then we have to either write some separate console application or keep going through the UI to test and see what happens.

Going through the UI is very time consuming and let’s face it, no one ever manually tests every possible scenario in every little corner of their application. You’d be ecstatic if even the happy path is tested at all.

Automated unit tests ensure that they run quickly and they all run. You basically save time, because you can cut down a lot on your manual testing time ( for all developers and testers in the team ), while making sure you test a lot more than via the manual way. So, no, adding unit tests does not add anything to your delivery, it just makes you deliver better quality, a lot quicker IF you have decent unit tests. Big IF there …

 

New article published in Dot Net Curry Magazine: https://dncmagazine.blob.core.windows.net/edition35/DNCMag-Issue35.pdf

Thank you,  Suprotim Agarwal, for your patience, this one took quite a bit of work!

This subject fascinates me. Lately I’ve seen lots of ads for courses or people who claim they can teach you how to become a software developer / designer / front end developer, you name it. The conclusion seems to be that anyone can do it.

This is born from the huge demand for developers of all kinds, demand which increases every year. New companies are born all the time, new products built so yes the demand gets higher and higher.

There is also the realization that the engineers produced by universities are not taught what they need and can’t write any kind of useful code. They go on to companies who then have to train them like you would train someone who has never seen a programming language in their life. Maybe this is 100% true, maybe not, there are always people who are better and some who waste their time going through a few years of advanced learning. This is not the point I want to discuss.

What I want to discuss is if anyone can become a developer. Can we take someone off the streets ( not literally although it has been done that way as well!) and teach them how to code? Is this the answer to the huge demand of developers everyone faces?

Let’s delve into this a little. What does one need to become a developer? Well first you need to learn a programming language.  You can’t write anything unless you know a language, right?

Can anyone learn a programming language? I believe the answer to this question is yes. Anyone can learn the basic blocks, how to write a for loop, an if statement, how to add numbers etc. One could go on and write simple programs which do a few things, like implement an algorithm of some kind. Of course knowing a programming language properly means a lot more then a few basic things.

You could get dragged into learning how to manage memory properly which pushes you into learning how computers actually work. Maybe you get to the point where you understand what a high level programming language is and maybe you understand what binary is and how come that a computer can understand what you ask it to do and actually does it. Maybe you understand these things and maybe not. The point is, do you want to understand these things?

Maybe you write an algorithm and are suddenly interested to see if you can make it faster and more efficient. Do you have the inquisitive mind which simply needs to understand how something works, or are content to see that it works and you don’t really care how.

I believe that in order to be a successful software developer of some kind, you need to have the aptitude for it. Creating something in this world is about creating an abstract model, imagine it all work and then implement it. That’s why a lot of very experienced developers will tell you that before you write any code, first go ahead and draw it on paper or on a board, imagine it like that first and once you figure out everything, only then sit down and actually write any code.

If you come from a maths background, whether you know it or not, that’s a very good sign that you can be a developer. Why do I say this? Because maths is all about the thinking process, it’s about abstract thinking, it’s about modelling and going from one known thing to another. If you have all these things then that’s a good indication you can be a developer, although it is not 100% guaranteed. I have seen very smart people with amazing background fail miserably in this field, because of their attitude and because of their inability to learn once they had it in their minds they knew everything better than anyone else. This happens because development is an ongoing process, once you get into it, you keep learning and learning and learning.

Learning never stops.

That’s what makes it harder than other disciplines. Sometimes it leads to burnout because you wake up one day and realize there’s no way you can keep up and there’s no way to know everything. Maybe you wake up one day and realize that you just can’t be bothered anymore.

So far I’ve talked about development as in back end development, I bet i am going to be told that front end is different, you can be a designer or front end dev  without all this, right?  I have seen the ads, learn a little bit of HTML and you’ll be guaranteed a job. I beg you, don’t fall for those. Web design is hard as well, you not only need to learn several things (  big surprise there ) but now you have to deal with other things, like browser differences. How come this box looks one way in Chrome and completely different in IE, or it works in Firefox but doesn’t work in Opera. You need to know JavaScript and that is a challenge because of the nature of the language. It also pushes you into back end development where everything I said before applies because guess what … JavaScript is just another programming language. Yes it runs in the browser but it is still a language.

At this point you might wonder, hang on a minute, are you trying to push me away from trying to become a developer? The answer is not exactly no, I want you to know what you’re getting into. Yes the salaries in IT are great, but if you don’t enjoy the field, you’ll never be more than an average level developer and won’t get any joy out of it. I want you to understand what these things mean and make you sit down and think if this is for you. If it is, great then go ahead and try.

Take the Yams challenge first though. Yams is a game with 5 dice, with poker like combinations. You can search more info about it and learn every little detail. I encourage you to write a program which implements this game in whatever language you want. Keep the interface simple.

If you can build a working version of this and enjoy yourself in the process then by all means you will love being a developer. You are in a great position because there is a lot of information out there, for free, about anything. You still need to figure out what you need though and how to do it.

Have I done it myself? Yes, I have. I did it before starting on my current path. I was actually working as a care coordinator at the time. I remember using Visual Basic 6 and winforms and I wrote the game for my wife. I absolutely loved it and it pushed me towards software development. I can only wish it does the same for you. Take the challenge and find out.

If you need some ideas, you can always use something like Visual Studio Community edition, or you can use JavaScript or anything else you want.

It’s up to you but the point is the tools won’t cost you anything.

Oh and let me know how it goes, if you do take the challenge.

Good luck!

What I would like to address today is the disconnect between the academia world and the professional world. We know a disconnect exists, we can hear countless employers complaining how graduates lack basic skills, how their attitude sucks etc.

What we don’t hear is how we are supposed to solve this problem. You know what they say, first admit there is a problem, then try to address it, right? This is exactly the purpose of this article.

Employers have an expectation that someone who graduated or is close to graduation needs to have a certain set of skills for them to become useful. They must know how to code, know multiple technologies, have the right attitude, be willing to do whatever. Is that a fair expectation? Maybe, maybe not.

What are students taught in universities? Granted, it’s been more than 20 years since I’ve been in one, but I remember being bored out of my mind. This is because I was being taught things I was not interested in. Later on, I took some courses with Open University, because for some reason I wanted a degree in UK. It was just as boring as I remembered it, actually even more boring. I wanted to learn stuff related to programming and I just gave up when I saw that one of my courses that I had to take was about design and I had to design a chair. That was something I was not interested in and I didn’t want to waste my time working on something that didn’t have any value for me.

This is one of the first topics, are we teaching the students what they need to know? I won’t pretend to be able to answer this question, perhaps others who studied recently can answer that a lot better than I can.

Employers expect someone to have a basic level of literacy, be able to read, write, know some maths and have a good worth ethic, meaning coming to work on time etc. They want to see an interest in programming and what they’ve been doing and working on to prove this interest actually exists. Just a look at grades on various subjects is not going to tell them much.

Someone who comes with great grades should be able to prove their value quickly otherwise what is the point, correct?

For a software developer to be successful there are a number of things they need to know. Imagine a web developer: they need to know some back-end language. Many universities happily teach Java and they have been doing it for a long time. If the job is that of a web developer, knowing Java is not going to help you that much.

You need to know front end stuff, you need JavaScript, you need HTML, CSS.

Then, how about Ajax and then what about relational or no-sql databases?

How about another scripting language?

How about the latest and greatest Open Source stack?

Hang on a minute, but what about mobile, responsive websites, how about hybrid and native?

I can keep going like this for a while, trust me, the list of skills can be endless. So, is that a fair expectation for a graduate to know all that? No, of course not, even if they dedicate their entire university career to these skills, it will still not help much, because, of course, by the time they finish their studies, the development stack has changed. Right? Well, that is true up to a point. There are a number of things and technologies that have been around for a while and they are still in use and in demand.

I will make a few statements here, which are my opinion and need to be taken perhaps lightly. I think that yes, software students need to learn more than what they are being taught right now, assuming they are not already! They need to have an understanding of a back-end language, such as Java or Dot Net. I would argue in favor of Dot Net and I will get back to this later.

Then they need at least  a basic understanding of JavaScript and perhaps an understanding of one MVVM framework. Which one is a bit unimportant. The point is that once you understand the concept, it becomes a lot easier to learn whatever the flavor of the month is and this is exactly the point. MVVM is everywhere these days and the concept takes a total shift from traditional methods. i know first hand how difficult it can be, I remember what it took for me to wrap my head around how it works.

Next, an understanding of relational databases is extremely important, they’re not going away any time soon.

Once they know these things here comes the most important thing and this is exactly what I believe is missing : an understanding of how these things work together. You do not learn one thing in a big vacuum. Everything one learns needs to help create a bigger picture. Developing a professional application these days is not done with the use of any one technology. There are multiple technologies and they all need to play together nicely.

For example, you learn about relational databases and you learn about dot net. How do they work together is extremely important, how do I build an application which uses both, how do I build a data layer in that language and how do I make it work nicely with a relational database?

Yes, we hear every day how universities should teach concepts, not specific frameworks. Well that is not only incomplete ( you can’t teach a concept without writing some code in some language )  but also totally not useful. You go to work and they won’t ask you to show on a black board how a specific algorithm works, you’re going to be asked to build something. That particular something might use the algorithms you learnt, but that algorithm is only a small part of something much bigger.

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Big disclaimer, this article has been in my drafts folder for two years. Yup, completely forgot about it, just uncovered it today, so hmm maybe the time has come to finish it.

Have any of my views changed? Maybe yes, maybe not, I am not 100% sure their is a need for a back end language anymore, but I would argue that learning one may not be a bad idea anyway.

Back to the drawing board, what do we need the software students to have?

I would say that having some Maths background is a huge help. I cannot stress enough how important this is. I am not talking here about learning algorithms by heart. If you do a lot of Maths, what you end up with is a very useful way of thinking, you develop abstract skills you can apply in many fields, software development included.

It is very important to be able to visualise a problem and build a mental approach on how you would solve it. This is all software development is, solving one issue after another, after all.

So what I would say to a student is to write code, as much as you can, build something that helps you and keep building things. Keep learning, read books, follow developers, see what they do, what they build and what interests them. Start looking for jobs before you finish your degree and have something to show already. All these things will help.

Also, realise you are just starting on a very long journey, pace yourself and be prepared to keep learning for as long as you are a developer. Trust me, this will never change.

Thank you and good luck!